TWI480790B - Touch device and driving method thereof - Google Patents

Description

Touch device and driving method thereof

The present invention relates to a touch device and a driving method thereof, and more particularly to a touch device capable of switching a scanning line driving frequency and a driving method thereof.

With the rapid development and application of information technology, wireless mobile communication and information appliances, many information products have been transformed from traditional keyboards or mouse input devices to use for the convenience of portability, light weight and user-friendly operation. A touch panel is used as an input device.

Currently, touch panels can be roughly classified into resistive, capacitive, optical, acoustic, and electromagnetic touch panels. Among them, resistive touch panels and capacitive touch panels are the most common products. Taking a capacitive touch panel as an example, the driving line is sequentially driven, and at the same time, the signal is received by the sensing line to know the change of the capacitance value of the touched position on the touch panel, thereby determining the position touched by the user. .

Due to the development of communication technology, today's living environment is full of many electronic products that use wireless communication transmission. Such electronic products are often accompanied by many electromagnetic wave effects. When the electromagnetic wave frequency emitted by the electronic product is close to the scanning line driving frequency of the capacitive touch panel, the electromagnetic wave signal is easily coupled to the capacitive touch panel and becomes a noise of the touch sensing signal, thereby causing misjudgment of the touch position. .

The invention provides a touch device and a driving method thereof, which can change the scanning line driving frequency of the touch device, avoid the misjudgment of the touch position caused by electromagnetic wave noise interference, and have no problem of delay of the touch reaction.

The invention provides a touch device, which comprises a touch panel, a driving unit, a sensing unit, a storage unit and a control unit. The touch panel includes a plurality of scan lines and a plurality of sensing lines. The driving unit is coupled to the touch panel to drive the scan line on the touch panel. The sensing unit is coupled to the touch panel to perform touch detection on the touch panel to generate a touch signal. The storage unit stores a plurality of driving frequency setting data groups, wherein the driving frequency setting data groups correspond to different scanning line driving frequencies. The control unit is coupled to the driving unit, the sensing unit and the storage unit, and determines whether the touch device is interfered by noise according to the driving frequency setting data group of the touch signal and the scanning line driving frequency of the corresponding driving unit, and determines the touch device when the touch device is determined. When the noise is disturbed, the control driving unit switches the frequency of driving the touch scan line to other scan line driving frequencies.

In an embodiment of the invention, the control unit determines the touch position of the touch panel according to the touch signal and the driving frequency setting data group of the scan line driving frequency of the corresponding driving unit.

In one embodiment of the present invention, each of the driving frequency setting data groups includes a capacitance value database and a touch reference value, and the capacitance value database includes a capacitance value information of the touch panel corresponding to the driving frequency of the scanning line. The touch reference value indicates the capacitance value when the touch panel is not touched.

In an embodiment of the invention, the control unit further controls the touch signal. The number is converted into a digital signal, and it is determined whether the difference between the digital signal obtained by the touch panel and the touch reference value is greater than a threshold value. When the difference is greater than the threshold value, the touch device is judged to be miscellaneous. Interference.

In an embodiment of the invention, the threshold value is a difference between the digital signal obtained by the control unit and the touch reference value obtained by the touch signal corresponding to the touch position when the touch panel is touched.

In an embodiment of the present invention, when the control unit switches the touch signal when the touch panel is not touched, the difference between the digital signal obtained by converting the touch signal and the touch reference value of each driving frequency setting data group is greater than the threshold. At the time of the value, the control unit controls the driving unit to select the scanning line driving frequency corresponding to the driving frequency setting data group having the smallest difference as the driving frequency of the scanning line.

In an embodiment of the invention, the driving unit and the sensing unit perform touch detection on the touch panel by performing self-capacitive touch detection and then performing mutual capacitive touch detection.

The present invention also provides a driving method for a touch device. The touch device includes a touch panel and a driving unit. The driving unit is configured to drive a plurality of scanning lines on the touch panel. The driving method of the touch device includes the following steps. A plurality of driving frequency setting data groups are stored, wherein the driving frequency setting data group corresponds to different scanning line driving frequencies. Touch detection on the touch panel to generate touch signals. The data group is set according to the driving signal of the touch signal and the scan line driving frequency of the corresponding driving unit to determine whether the touch device is interfered by noise. When it is determined that the touch device is disturbed by noise, the control driving unit switches the frequency of driving the touch scan line to another scan line driving frequency.

In one embodiment of the present invention, the driving method of the touch device further includes determining a touch position of the touch panel according to the driving frequency setting data group of the touch signal and the scan line driving frequency of the corresponding driving unit.

In an embodiment of the present invention, each of the driving frequency setting data groups includes a capacitance value database and a touch reference value, and the capacitance value database includes a capacitance value information of the touch panel corresponding to a driving frequency of the scanning line, The control reference value indicates the capacitance value when the touch panel is not touched.

In an embodiment of the invention, the step of determining whether the touch device is subjected to noise interference according to the touch signal and the driving frequency setting data group of the scan line driving frequency of the corresponding driving unit comprises the following steps. Convert touch signals to digital signals. It is determined whether the difference between the digital signal obtained by the touch panel and the touch reference value is greater than a threshold value. When the difference is greater than the threshold value, it is determined that the touch device is interfered with by the noise.

In one embodiment of the present invention, the threshold value is a difference between a digital signal obtained by converting a touch signal corresponding to the touch position and a touch reference value when the touch panel is touched.

In an embodiment of the present invention, when the difference between the digital signal obtained by switching the touch signal and the touch reference value of each driving frequency setting data group is greater than the threshold when the touch panel is not touched, The control driving unit selects the scanning line driving frequency corresponding to the driving frequency setting data group having the smallest difference as the driving frequency of the scanning line.

In an embodiment of the present invention, the driving method of the touch device includes performing touch detection on the touch panel by performing self-capacitive touch detection and then performing mutual capacitive touch detection. .

Based on the above, the present invention switches the scan line driving frequency of the touch device according to the preset plurality of driving frequency setting data groups, so as to avoid the touch position misjudgment caused by electromagnetic wave noise interference, and there is no touch reaction delay. The problem.

The above described features and advantages of the present invention will be more apparent from the following description.

FIG. 1 is a schematic diagram of a touch device according to an embodiment of the invention. Referring to FIG. 1 , the touch device 100 includes a touch panel 102 , a driving unit 104 , a sensing unit 106 , a storage unit 108 , and a control unit 110 . The driving unit 104 and the sensing unit 106 are coupled to the control panel 102 , and the control unit 110 is coupled to the driving unit 104 , the sensing unit 106 , and the storage unit 108 . The touch panel 102 includes a plurality of scan lines and a plurality of sensing lines (not shown). In the embodiment, the driving unit 104 and the sensing unit 106 perform touch detection on the touch panel 102 by performing self-capacitive touch detection and then performing mutual capacitive touch detection.

When the self-capacitive touch detection is performed, the driving unit 104 simultaneously detects the change of the capacitance value of the scan line on the touch panel 102 to generate a touch signal, and the sensing unit 106 also simultaneously faces the touch panel 102. The sensing line generates a touch signal by detecting the change of the capacitance value, and the control unit 110 determines the touch position of the user according to the touch signal output by the driving unit 104 and the sensing unit 106. When performing mutual capacitive touch detection, the driving unit 104 sequentially drives the scanning lines, and the sensing unit 106 simultaneously detects the sensing lines. The control unit 110 determines the change of the capacitance value of each position on the touch panel 102 according to the touch signal output by the sensing unit 106, thereby determining the touch position of the user.

The storage unit 108 stores a plurality of driving frequency setting data groups, wherein the driving frequency setting data groups correspond to different plurality of scanning line driving frequencies. Since the different scan line driving frequencies will make the capacitance values sensed by the sensing unit 106 different, the control unit 110 must also perform the touch position determination of the touch panel 102 according to different driving frequency setting data groups. That is, when the driving unit 104 drives the scan line with the preset scan line driving frequency, the control unit 110 can determine the touch signal according to the corresponding driving frequency setting data group and the touch control panel 102 to determine the touch. position.

In detail, each driving frequency setting data group may include a capacitance value database (bank) and a touch reference value, and the capacitance value database includes capacitance value information of the touch panel 102 corresponding to the driving frequency of the scanning line, that is, The capacitance value seen by the sensing unit 106 at a specific scanning line driving frequency, and the touch reference value indicates a capacitance value when the touch panel 102 is not touched. When the control unit 110 receives the touch signal from the sensing unit 106, the control unit 110 converts the touch signal into a digital signal, and determines whether a touch event occurs according to the difference between the digital signal and the touch reference value. When the difference between the digital signal and the touch reference value exceeds a preset value, it can be determined that the position corresponding to the touch signal is touched by the user.

In addition, since the touch panel 102 of the present embodiment performs self-capacitive touch detection and then performs mutual touch detection, the touch position detection is performed, and the electromagnetic noise interference effect only occurs. Mutual touch detection The test appears. Therefore, the control unit 110 can also determine whether the touch device 100 is interfered by noise according to the touch signal and the driving frequency setting data group. That is, when the control unit 110 detects a non-touch event during self-capacitive touch detection, and detects a touch event when performing mutual capacitive touch detection, it represents a touch. The control device 100 is interfered by external electromagnetic wave noise.

In detail, the control unit 110 can determine whether there is noise interference by determining whether the difference between the digital signal obtained by the touch panel 102 and the touch reference value is greater than the threshold value, and when the digital signal is When the difference between the touch reference value and the touch reference value is greater than the threshold value, it means that the touch device 100 is interfered by external electromagnetic wave noise. The threshold value may be, for example, the difference between the digital signal obtained by the touch panel 102 when touched and the touch reference value. However, the actual application is not limited thereto, and may be set to be larger or larger according to actual conditions. Small threshold value.

After the control unit 110 determines that the touch device 100 is subjected to noise interference, the control unit 110 can control the driving unit 104 to switch the frequency of driving the touch scan line to another preset scan line driving frequency, that is, the driving frequency setting data group. The scan line drive frequency corresponding to the group. Since the storage unit 108 has previously stored the drive frequency setting data groups corresponding to different scan line drive frequencies, after the drive unit 104 switches to different scan line drive frequencies, the control unit 110 can immediately apply different scan line drive frequencies. The touch position judgment parameters (such as the capacitance value database and the touch reference value) do not have a delay in the touch response caused by switching the scan line drive frequency.

In addition, if the control unit 110 finds that the difference between the digital signal obtained when the touch panel 102 is not touched and the touch reference value of each driving frequency setting data group is greater than the threshold value, the control unit 110 can control the driving. The unit 104 selects the scan line driving frequency corresponding to the driving frequency setting data group having the smallest difference as the driving frequency of the scanning line, that is, selects the scanning line driving frequency which is least affected by the electromagnetic wave noise interference as the scanning line. Drive frequency.

2 is a flow chart of a driving method of a touch device according to an embodiment of the invention. Referring to FIG. 2 , the method for driving the touch device 100 described above may include the following steps. First, a plurality of driving frequency setting data groups are stored (step S202), wherein each driving frequency setting data group respectively corresponds to different scanning line driving frequencies, and each driving frequency setting data group includes a capacitance value database and a touch reference The value, the capacitance value database includes the capacitance value information of the touch panel corresponding to the driving frequency of the scan line, and the touch reference value indicates the capacitance value when the touch panel is not touched.

Then, the touch panel is touch-detected to generate a touch signal (step S204). Then, the data group is determined according to the touch signal and the driving frequency of the scan line driving frequency of the corresponding driving unit to determine whether the touch device is subjected to noise interference (step S206).

Further, in step S206, the touch signal can be converted into a digital signal, and then the difference between the digital signal obtained by the touch panel and the touch reference value is greater than the threshold value. When the difference between the digital signal and the touch reference value is greater than the threshold value, it is determined that the touch device is interfered by noise. Conversely, if the difference between the digital signal and the touch reference value is not greater than The threshold value determines that the touch device is not disturbed by noise. The threshold value can be, for example, the difference between the digital signal obtained by converting the touch signal corresponding to the touch position and the touch reference value when the touch panel is touched, but not limited thereto.

If it is determined that the touch device is not interfered by the noise, the touch position of the touch panel is determined according to the touch signal and the driving frequency setting data group of the scan line driving frequency of the corresponding driving unit (step S208). If it is determined that the touch device is disturbed by noise, the control driving unit switches the frequency of driving the touch scan line to another scan line drive frequency (step S210).

In addition, when the difference between the digital signal obtained by switching the touch signal and the touch reference value of each driving frequency setting data group is greater than the threshold when the touch panel is not touched, the control driving unit has the smallest selection. The driving frequency of the difference sets the scanning line driving frequency corresponding to the data group as the driving frequency of the scanning line to minimize the influence of the noise interference of the electromagnetic wave.

In summary, the present invention switches the scanning line driving frequency of the touch device according to a preset plurality of driving frequency setting data groups, so as to avoid misidentification of the touch position caused by electromagnetic wave noise interference, and since the storage unit has been previously The driving frequency setting data group corresponding to different scanning line driving frequencies is stored, and the control unit can immediately apply the touch position determining parameters corresponding to different scanning line driving frequencies without delay of the touch reaction caused by switching the scanning line driving frequency. The situation happened.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and any one of ordinary skill in the art does not deviate. In the spirit and scope of the present invention, the scope of protection of the present invention is defined by the scope of the appended claims.

100‧‧‧ touch device

102‧‧‧Touch panel

104‧‧‧ drive unit

106‧‧‧Sensor unit

108‧‧‧ storage unit

110‧‧‧Control unit

S202~S210‧‧‧Touch device driving method steps

FIG. 1 is a schematic diagram of a touch device according to an embodiment of the invention.

2 is a flow chart of a driving method of a touch device according to an embodiment of the invention.

S202~S210‧‧‧Touch device driving method steps

Claims (14)

A touch device includes: a touch panel comprising a plurality of touch scan lines and a plurality of sensing lines; a driving unit coupled to the touch panel to drive the scan lines on the touch panel; The measuring unit is coupled to the touch panel, and performs touch detection on the touch panel to generate a touch signal; a storage unit stores a plurality of driving frequency setting data groups, wherein each of the driving frequency setting data groups Having a corresponding scan line driving frequency; and a control unit coupled to the driving unit, the sensing unit and the storage unit, and setting data according to the touch signal and a driving frequency corresponding to a scan line driving frequency of the driving unit The group determines whether the touch device is interfered by noise. When it is determined that the touch device is interfered by noise, the driving unit controls the driving unit to switch the frequency of driving the touch scan lines to other scan line driving frequencies. . The touch device of claim 1, wherein the control unit determines the touch of the touch panel according to the touch signal and the driving frequency setting data group corresponding to the scan line driving frequency of the driving unit. position. The touch device of claim 1, wherein each of the driving frequency setting data groups includes a capacitance value database and a touch reference value, and the capacitance value database includes driving frequencies corresponding to the scanning lines. a capacitance value information of the touch panel, the touch reference value indicating the touch surface The value of the capacitor when the board is not touched. In the touch device of claim 3, the control unit further converts the touch signal into a digital signal, and determines the digital signal obtained by the touch panel when the touch panel is not touched and the touch Whether the difference of the reference value is greater than a threshold value, and when the difference is greater than the threshold value, determining that the touch device is interfered by noise. The touch device of claim 4, wherein the threshold value is the digital signal obtained by the control unit converted to the touch signal corresponding to the touch position when the touch panel is touched, and the touch signal Control the difference between the reference values. The touch device of claim 4, wherein the control unit converts the digital signal obtained by the touch signal to the driving frequency setting data group when the touch panel is not touched When the difference between the touch reference values is greater than the threshold value, the control unit controls the driving unit to select the scan line driving frequency corresponding to the driving frequency setting data group having the smallest difference as the driving frequency of the scan lines. . The touch device of claim 1, wherein the driving unit and the sensing unit perform self-capacitive touch detection and then perform mutual capacitive touch detection. The panel performs touch detection. A driving method of a touch device, wherein the touch device includes a touch panel and a driving unit, wherein the driving unit is configured to drive a plurality of touch scan lines on the touch panel, and the driving method of the touch device includes : storing a plurality of driving frequency setting data groups, wherein each of the driving frequency setting data groups has a scanning line driving frequency corresponding thereto; Performing touch detection on the touch panel to generate a touch signal; determining whether the touch device is subjected to noise interference according to the touch signal and the driving frequency setting data group corresponding to the scan line driving frequency of the driving unit; And when it is determined that the touch device is interfered by the noise, the driving unit is controlled to switch the frequency of driving the touch scan lines to the other scan line driving frequencies. The driving method of the touch device of claim 8, further comprising: determining the touch of the touch panel according to the touch signal and the driving frequency setting data group corresponding to the scan line driving frequency of the driving unit Control position. The driving method of the touch device of claim 8, wherein each of the driving frequency setting data groups includes a capacitance value database and a touch reference value, and the capacitance value database includes corresponding scanning lines. a capacitance value information of the touch panel of the driving frequency, the touch reference value indicating a capacitance value when the touch panel is not touched. The method for driving a touch device according to claim 10, wherein determining whether the touch device is subjected to noise interference according to the touch signal and a driving frequency setting data group corresponding to a scan line driving frequency of the driving unit The step of converting the touch signal into a digital signal; determining whether the difference between the digital signal obtained by the touch panel and the touch reference value is greater than a threshold value; When the difference is greater than the threshold, it is determined that the touch device is interfered by noise. The driving method of the touch device according to claim 11, wherein the threshold value is a digital signal obtained by converting the touch signal corresponding to the touch position when the touch panel is touched The difference between the touch reference values. The method for driving a touch device according to claim 11, wherein the digital signal obtained by converting the touch signal and the driving frequency setting data group when the touch panel is not touched When the difference between the touch reference values is greater than the threshold value, the driving unit is controlled to select the scan line driving frequency corresponding to the driving frequency setting data group having the smallest difference as the driving frequency of the scan lines. The driving method of the touch device as described in claim 8 includes performing touch detection on the touch panel by performing self-capacitive touch detection and then performing mutual capacitive touch detection. .